The present study surveyed adult caddisflies in Ile-Ife to identify the species that contribute to the fauna of freshwater ecosystems of this area and to determine their seasonal abundance. Adult caddisflies were collected between June 2009 and November 2010 from eight sampling stations established at different locations using an improvised light trap. A total of 754 adult caddisflies that were collected represent six species in six genera and three families. The species identified are Dipseudopsis conformis Navas, 1931, Polymorphanisussimilis Ulmer, 1912, Aethaloptera dispar Brauer, 1875, Ceraclea njalaensis (Mosely, 1933), Pseudoneureclipsis mlangensis Mosely, 1939 and Cheumatopsyche digitata (Mosely, 1935). The Hydropsychidae was represented by three species belonging to three genera. The hydropsychid C. digitata was the dominant and most widely distributed species, occurring at all sampling stations with the highest frequency of occurrence (51%). On the other hand, P. mlangensis (Dipseudopsidae) was the least abundant with the lowest frequency of occurrence (0.8%).

Oecophylla spp. are used as biocontrol agents for many types of insect pests. A large and stable population is essential for effective control of pests. Colonies of Oecophylla spp. can be transplanted from wild habitats into orchards. Transplanted colonies can only survive in the presence of egg laying queens. It is difficult to locate nests with egg laying queens in large colonies that may sometimes contain more than 100 nests. Therefore, the need to explore and develop methods for rearing newly mated queens in nurseries may not be over emphasized, hence the current study. In the first experiment, we tested three rearing methods on queen survival and colony establishment. In the second experiment, we compared feeding techniques of different weaver ants on young colony growth. We observed that queens were best reared under continuous, indirect access to water. The first workers emerged earlier (32 days on average) in indirect and direct continuous access to water methods than on limited access to water (sprinkled) (38 days on average). Moreover, rearing mated queens under continuous indirect access and continuous direct access to water methods saved labour and time, because of limited attendance to the colonies. Availability of water, sugar solution and different sources of protein throughout improved the growth of young colonies. Likewise, the number of workers increased rapidly. Therefore rearing mated queens in nurseries is possible and would minimize hustles in hunting for the colonies and their queens in the wilderness.

The leaf-eating caterpillar, Opisina arenosella Walker, is the most destructive pest of coconut palm in India and Southeast Asia. The management practices employed against O. arenosella so far have been unsuccessful in many instances in India, due to the pest behaviour and coconut palm phenology. The life cycle, incidence and behaviour of O. arenosella are rather interesting and useful for the intervention of pheromone trapping technique for its management. We conducted the present study with the intention of identifying the female sex pheromone of O. arenosella and testing its efficacy under field conditions. Gas chromatography coupled electroantennographic detection (GC–EAD) and gas chromatography–mass spectrometry (GC–MS) analysis of female pheromone glands extract of one-day-old O. arenosella females confirmed the presence of (Z,Z,Z)-3,6,9-tricosatriene (Z3Z6Z9-23Hy) as the dominant sex pheromone component. The male antennal response to female pheromone gland extract and synthetic Z3Z6Z9-23Hy was recorded using GC–EAD, and the results revealed that antennal response was positive to both the treatments at 0.13 mV and 0.14 mV respectively, compared to control (air), which was 0.016 mV. It was also evident from wind-tunnel experiments that the male moth response was high (80%) with the female gland extract, compared to 60% with synthetic pheromone and 0% for control (air). Male moths caught in the traps with and without lure were assessed in two field sites and recorded 69.26% and 54.25% more moth catches in the traps with the lure. We also observed a similar result in the cage experiment in which male moths caught in the traps with and without lure were 64.50% and 12.40%, respectively. The study also confirmed that 93.20% moths caught in the pheromone-baited traps were male. From the study, it is evident that the presence of (Z,Z,Z)-3,6,9-tricosatriene, which is the sex pheromone compound from the female gland extract of O. arenosella, is an effective attractant in pheromone traps for the male moth under field conditions.

Focal species are valuable tools for evaluating management practices for biodiversity conservation. Butterfly gardening through the creation of appropriate habitats can be a primary conservation tool to increase species abundance and richness and gene flow among the populations in fragmented landscapes. In this context, the role of butterfly gardens in the conservation of butterfly populations and the seasonal population trends of swallowtail butterflies (family Papilionidae) sighted in the Butterfly Safari Park at Thenmala were studied. A total of 4760 sightings of 15 species of swallowtails belonging to five genera were recorded, of which six were endemic species, three species had protected status and two were rare species. It is worth noting that of the 19 species of the papilionids recorded in Kerala, as many as 15 species were recorded in Thenmala. Of the various species recorded, Troides minos, Pachliopta pandiyana, Pachliopta aristolochiae, Graphium agamemnon, Graphium sarpedon, Papilio polytes, Papilio clytia, Papilio demoleus and Papilio polymnestor comprised the resident populations, while species such as Atrophaneura hector, Papilio helenus, Papilio dravidarum, Papilio paris, Papilio liomedon and Graphium nomius were found only during certain seasons. The overall butterfly abundance was high from August to November. The butterfly populations exhibited a gradual decline in numbers from December onwards with the onset of dry seasons. The abundance of butterfly populations was low during March–April. The abundance of T. minos, P. pandiyana, P. polymnestor, P. paris, P. dravidarum, P. helenus, P. polytes and P. liomedon showed a significant negative correlation with monthly average temperature and a significant positive correlation with humidity.

Effects of pesticidal plant extracts on non-targeted species are rare. Direct topical and residual sprays of crude aqueous extracts of three pesticidal plants: Datura stramonium L. Bobgunnia madagascariensis Kirkbr. & Wiersema and Solanum delagoense L. were assessed in laboratory bioassays and on-station experiments against the ladybird beetle, Hippodamia variegata (Goeze). The plants are routinely used by smallholder vegetable farmers to control aphids, Brevicoryne brassicae L. attacking rape, Brassica napus L. The crude extracts of D. stramonium fresh leaves, S. delagoense fresh fruits and B. madagascariensis dried pods, were applied separately at 5, 10, 15, 20 and 25% w/v under laboratory conditions. Application rates of 20% and 25% w/v of the plant extracts were further evaluated on-station. Negative (tap water) and positive (dimethoate® (36% E.C)) controls were included for comparison. The mortality of H. variegata was recorded 24, 48 and 72 h post-exposure. In on-station experiments, treatments were applied fortnightly and live H. variegata adults were counted at 1, 7 and 14 days post-application. Mortality of H. variegata in laboratory bioassays increased with increase in post-exposure time and B. madagascariensis (25% w/v) caused the highest mortality. Based on LD50 values, B. madagascariensis extracts were most toxic (LD50, 30% w/v) followed by D. stramonium (LD50, 34% w/v) and S. delagoense (LD50, 49% w/v) 24 h post-application. In on-station experiments, the synthetic chemical significantly lowered (P < 0.05) H. variegata numbers compared to the negative control and plant extracts. The results showed that D. stramonium and S. delagoense extracts at the application rates used in the study were relatively safer to H. variegata than B. madagascariensis (25% w/v); hence, the former two plants can be included in integrated pest management programmes.

Jatropha curcas L. is a stem-succulent shrub that produces high concentrations of seed oils that are convertible into biodiesel. In this study, the incidence of four insect pests on Jatropha, Strabala rufa, Gnathamitermes tubiformans, Pempelia morosalis, and Acanthoplus discoidalis was recorded over three years in a semi-arid climate in Gaborone, Botswana. The occurrence of these insects was concentrated in the summer season from October to April, while lower numbers of all species were found in May as the temperature began to reduce towards the winter season, suggesting that insect pests of Jatropha exhibit a unique temporal pattern in this region. A considerable variation was observed among Jatropha accessions regarding the insect pest occurrence, indicating a vast difference in the susceptibility to insect pests among Jatropha accessions.

The relationships between estimates of tsetse challenge and trypanosome prevalence in trypanotolerant and susceptible cattle were examined at sites of the African Trypanotolerant Livestock Network. Estimates of tsetse challenge were determined as the product of tsetse relative densities, their trypanosome infectionrates and the proportions of feeds taken by them from cattle. Trypanosome prevalence in both trypanotolerant and susceptible breeds of cattle was estimated from monthly examination of groups of ear-tagged cattle. Regression equations between estimates of trypanosome prevalence and tsetse challenge were fitted using an arcsin transformation of trypanosome prevalence and a log10 transformation of tsetse challenge. Highly significant relationships between estimates of tsetse challenge and trypanosome prevalence were found for sites with trypanotolerant cattle (P < 0.0001) and sites with susceptible cattle (P < 0.01). Mean trypanosome prevalence at a given level of tsetse challenge was at least twice as high in susceptible as in trypanotolerant cattle. The slopes of the regression lines for the two groups of cattle were significantly different (P < 0.05). The results confirm the superior ability of trypanotolerant cattle to withstand tsetse challenge in the field. The curves obtained for the two groups of cattle illustrate the necessity in tsetse control campaigns for a major reduction of tsetse populations to take place before significant decreases in trypanosome incidence in livestock can be achieved.

A survey carried out over Western Kenya in order to determine the prevalence of microorganisms in cereal stem borers and legume pod borer showed the presence of a large number of insect pathogens in the dead larvae. Larval cadavers were recovered from all sampling sites. Bacterial and fungal microorganisms were highly prevalent. Other major groups of microorganisms were also recovered, although at a low level. Viruses (polyhedral inclusion bodies and granulosis viruses) occurred at 2.7% at the Mbita Point Field Station, and 1.1% in the field. Mermithids and rhabditids occurred at 0.4% in the station and 0.6% in the field, whereas the protozoans (microsporidia and gregarines) were more prevalent in the station than in the farmers' fields (9.4 and 1%, respectively).

The spotted stalk borer, Chilo partellus was the most common borer sampled, but Busseola fusca and legume pod borer, Maruca testulalis were sampled in most sites too. Sesamia calamistis and EIdana saccharina were recorded at a low level, and C. orichalcoceliellus was recorded only at the Kenya coast.

The systematics of phlebotomine sandflies have significantly advanced in the last two decades through the incorporation of a growing body of information on the biology of sandflies and the introduction of new techniques: chromosome analysis, enzyme electrophoresis, detailed morphological studies, laboratory rearing and colonization, and multivariate morphometrics. These techniques have been used mainly in the study of intra-specific variation of vector species. The rôle of sandfty systematics in the epidemiology of leishmaniasis is discussed.

The influence of banana weevil, Cosmopolites sordidus (Germar)(Coleoptera: Curculionidae), population density on oviposition rates and larval survivorship was studied in the laboratory at the Kawanda Agricultural Research Institute in Uganda. This study was undertaken to elucidate the relationship between density-dependent factors and rates of banana weevil increase in the field. Oviposition substrates (corm pieces) were offered to a range of densities of weevils maintained in buckets. Mean oviposition rates per female at densities of 10, 20 and 40 females per bucket were 29, 37 and 53%, respectively, lower than that at a density of 5 females. Nevertheless, total oviposition for the same groups was 1.4, 2.5 and 3.7 times higher than that of the 5-female group. Providing fresh corms daily instead of every five days did not increase oviposition. Larval survivorship was slightly higher at lower densities of immatures following insertion of different densities of eggs or first instars into banana corms. The results suggest that density-dependent factors can influence oviposition rates of individual weevils and survivorship of immatures, but appear to exert only modest influence in reducing banana weevil population growth. More likely, high mortality of weevil immatures under field conditions and/or higher rates of adult mortality and emigration than previously postulated contribute to the slow population build-up of this pest.

Six cowpea cultivars, TVu 1890, TVu 1, TVx 3343-03E, IT82E-9, VITA-3 and Ife Brown, with different responses to infestation and damage by pod-sucking bugs (PSBs) were studied for the biophysical and biochemical characteristics of pod that may be involved in this differential response to feeding by PSBs. Tough pod wall, requiring a force of 25 newtons/mm2 to penetrate at pod maturity, is considered to be an important factor contributing to the lesser PSB feeding damage observed in the cultivar TVu 1890. The phenolic content of the pods of the studied cowpea cultivars was not correlated with their tannin content. Furthermore, no correlation could be established between the tannin content in the pod and the level of susceptibility of the cowpea cultivars to infestation and damage by PSBs. While tannins are considered to be important in conferring certain types of anti-herbivory properties to a number of plants and crop varieties, our findings suggest that in the cowpea cultivars studied, phenols in addition to the tough pod wall may be more important in conferring resistance to PSBs.

Plant resistance research requires many entomological and plant breeding techniques and methodologies of which some are critical to the success of the programme. The entomologist has the responsibility of developing techniques for: providing sufficient numbers of insects for screening and other plant resistance studies; creating uniform and controlled populations of the test insect for identifying and developing resistant germplasm; measuring resistance; and determining mechanisms and bases of resistance. A thorough knowledge of the insect-host plant relationship is essential for developing efficient techniques. Some of the considerations involved in developing these techniques are discussed with selected examples to illustrate various techniques employed in plant resistance to insects research.

As a background to an IPM project, this paper describes pesticide treatment of cotton in Sudan Gezira, starting in 1945/46. Until the end of the 1950's, one treatment per season was sufficient to control the only important pest, the jassid, Empoasca lybica, but the number of treatments increased during the 1960's (from 3 to 5) and has since the early 1970's been 6–9.

The continuous use of pesticides has resulted in changes of the pest complex, ultimately creating “hyper” pests such as the whitefly (Bemisia tabaci), cotton bollworm (Heliothis armigera) and aphids (Aphis gossypii). The increase in number of applications of pesticide is coupled with the rising costs of pest control and a stagnant yield. The stickiness problem created by the honey dew of whitefly and aphids increased with the rising number of sprays. The exclusive use of chemical control not only failed to improve the quality or quantity of the yield, but put a great strain on the national economy as well.

The Sudan therefore requested the FAO to initiate an IPM project starting in 1979, with financial support from the Netherlands. During the past 2 years support has also been given by the World Bank. The IPM approach has given very valuable results during the last two seasons when large (more than 100 acres) plots in the Gezira and Rahad Schemes were left unsprayed with the objective of investigating the potential of the natural enemies in the absence of pesticides, and to compare findings with population trends of pest and beneficial organisms in the fields subjected to conventional chemical control.

The first significant finding was that Bemisia tabaci and Aphis gossypii can be managed at desirable levels by their indigenous natural enemies, and that their outbreaks are attributed to the decimation of these natural enemies by chemical treatment. Populations of beneficial arthropods were consistently much lower in the fields which received regular pesticide applications.

The result of the large-scale experiments indicate that Empoasca lybica is the only really damaging pest (“key pest”) in the Gezira because of the absence of natural enemies to regulate its population. Control of E. lybica in the 1940's and 1950's resulted in the creation of Heliothis armigera as a major pest. This situation necessitated early season applications of pesticides to suppress H. armigera, which further reduced the role of the natural enemies of B. tabaci and A. gossypii. Both have developed into major pests of regular occurrence.

Cotton farmers in Gezira are now faced with a complex of very serious pests. In order to solve this problem, we will have to make drastic changes in pest control strategies and to adopt an IPM approach as soon as possible. The biological control H. armigera is considered as first priority in order to avoid the early season application of pesticides. Trichogramma pretiosum was introduced from the USA and released in the Rahad Scheme in 1988/89. The preliminary results are very promising.

Cultural and biological control of E. lybica will be attempted in order to further reduce pesticide applications. The control of this pest by the use of “milder” pesticides is also included in the programme.

The presently used threshold levels for all major pests are very low, and are under revision through properly conducted large-scale experiments.

Crude fractions of aerial parts of Andrographis paniculata (Burm.f.) (Acanthaceae) were evaluated for antifeedant, growth-inhibitory and oviposition-deterrent activity against larval and adult stages of the Bihar hairy caterpillar, Spilarctia obliqua (Arctiidae). The methanol fraction had the highest growth-inhibitory activity. Further fractionation resulted in nine sub-fractions of which the most active, identified as the diterpene andrographolide, displayed significant growth-inhibitory and antifeedant properties with GI50 and FD50 values of 100.4 and 159.7 μg/g diet respectively. The ethyl acetate fraction possessed the highest oviposition-deterrent activity.

Per cent survival, larval period and weight, pupal duration and weight, emergence, adult longevity and fecundity of Heliothis armigera (Hubner) were affected by the pulse species on which it was reared. The pulses could be classified into two groups i.e. pigeon pea and chick pea which were suitable for growth, development and fecundity and black gram, sweet pea, green gram, broad bean and lentil which were unsuitable.

Diversity amongst the different populations is one of the problems in the control of medically important mosquitoes. Wing morphometry was used to identify within-species variation amongst some populations of Aedes aegypti in three areas of Lagos State, Nigeria. Ten landmarks on the right wing of adult female Ae. aegypti mosquitoes were digitized using TPSdig software. Relative distances of the veins and interpoints were calculated as well as the Euclidean distances based on these relative distances. In three (50%) of the interpoints, the relative distances were significant (P<0.05) to both the Brown–Forsythe F ratio and Welch ANOVA. The highest Euclidean distance of 7.738 was between Ebute Metta 2 and Badagry; the lowest of 4.426 was between Ikorodu and Ebute Metta 2. The distance between Ebute Metta 1 and Ebute Metta 2 was 5.867, which is more than the distance between Ebute Metta 2 and Ikorodu. Three groups of Ae. aegypti were identified, and the differences in lengths and interpoints observed on the wing veins suggest a possible morphological divergence amongst populations.

A year round ecological study of Glossina morsitans submorsitans variety ugandensis was carried out from September 1980 to August 1981 in the Finchaa river valley in the western part of Ethiopia. Two sampling methods, namely vehicle patrol and screen/handnet capture were employed. The latter was more efficient. The effect of various environmental factors (e.g. altitude, climate, vegetation etc.) that determine the eco-distribution of this species of tsetse were analysed. The most significant finding was that tsetse were distributed far above the previously known altitude limits.

Studies of cocoa tree genetic resistance to attack by Scihlbergella singularis (Haglund.) (Hemiptera: Miridae), have so far been based on field observations of cultivar performance. Although this approach was useful in guiding breeding programmes, observations on tree crops are time-consuming (3–4 years) and labour-intensive. Thus a standard laboratory microassay method based on a study of the mirids’ dietary preferences was developed to quantify the attractiveness of cocoa trees to mirids under controlled conditions, with reproducible results.

A dual approach was taken to establish relations between laboratory data and field observations: preliminary cultivar sorting of both clones and hybrids in the laboratory, by microassays was combined with an eight-year observation programme in two different ecological zones in Ivory Coast: on the shores of a lagoon (Bingerville) and under thinned forest in Basse Côte (Divo). In Cameroun only clones from IRA field station at Nkoemvone were tested by microassays.

After three successive sets of field observations, a comparative analysis of the results revealed close correlations between cultivar responses in microassays and those observed in the field.

Cultivar responses to mirids revealed that there are two performance groups within the planting material selected, viz., in increasing order of attractiveness, Forasteros (upper and lower Amazon cultivars) and Trinitarios.

In Cameroon, microassays revealed behavioural polymorphism amongst the cultivars tested: plants of the same origin can react very differently to mirids as it was the case for the local trinitarios SNK group.

The microassay technique is quick and easy to use, and is effective for the early selection of mirid-tolerant plant material.

The effects of various levels of cow manure (equivalent to 0–50 kg nitrogen/ha.) or ground limestone (equivalent to 0–5 tons calcium/ha.) on the expression of resistance of cassava, Manihot esculenta Crantz to the cassava mealybug, Phenacoccus manihoti Mat. Ferr., were investigated under semi-controlled conditions in the laboratory. The study was made on two varieties of cassava, Moudouma and MM79, characterized by different levels of resistance in terms of antibiosis and tolerance. The antibiotic component was evaluated by determining the intrinsic capacity for increase rc and tolerance by quantifying morphological and physiological modifications in the growth of plants induced by 2 months infestation by 100 mealybugs.

The antibiotic resistance of the two varieties was reduced by both fertilizers. However, the reduction was only significant at levels of 10 and 20 kg N/ha. and 1 and 1.51 Ca/ha. for Moudouma and MM79 respectively.

In both varieties, tolerance was increased by the addition of nitrogen and not modified by the addition of lime.

The integration of these results into traditional cassava crops systems has also been discussed.

Bioassays against the fourth instar larvae of mosquito, Culex pipiens pipiens showed that the non polar part of the duck weed, Lemna minor extracts has a high insecticidal action. On the other hand, these extracts contained synomones of the duck weed which repelled the ovipositing females. By using concentrations equivalent to LC25, the survival resulting by the n. hexane was the least. The tolerance for the sublethal doses was associated with malformations in all stages. First instar larvae and recent pupae were more susceptible to the duck weed synomones than the other larval instars. The duck weed synomones repelled the ovipositing females of Piophila casei and have had an insecticidal effect on larvae and reduced resulting adults. When larvae of Spodoptera littoralis were subjected to sublethal doses of duck weed extract, malformations in the subsequent stages were found.